基于AlGaN/BP/MoS2范德华异质结的单片集成紫外-红外双波段探测器研究

Ultraviolet-Infrared dual-band photodetectors have significant applications in both military field and national economy. However, right now the performance of AlGaN based Ultraviolet-Infrared dual-band photodetectors is limited by the low responsivity and large dark current due to the low crystal quality of the materials, the unoptimized device structure and the work principle. In this project, a novel monolithic integrated Ultraviolet-Infrared dual-band photodetector based on AlGaN/BP/MoS2 van der Waals heterojunction is proposed. Taking advantage of no lattice match requirement for van der Waals heterojunction, the 2D BP/MoS2 pN junction can be integrated onto the 3D AlGaN PN junction to form an npPN type back-to-back photodiode via the layer-stacking technique, in order to detect the Infrared and Ultraviolet radiation simultaneously. We will investigate the epitaxy and defect control mechanisms for the growth of high quality high Al-content AlGaN film. Meanwhile investigate the influences of AlGaN doping, BP and MoS2 thicknesses and interfacial defects on the performance of photodetector in detail. Via the band engineering, interfacial defects control engineering, as well as improving the material epitaxy, 2D material transfer and device fabrication techniques, a monolithic integrated Ultraviolet-Infrared dual-band photodetector with high performance and fast response speed will be fabricated, which may provide new scheme and method for the development of high-performance Ultraviolet-Infrared dual-band photodetectors.

紫外-红外双波段探测器在军事领域和国民经济中均有着重要的研究价值和广泛的应用前景。然而，由于材料晶体质量、器件结构及工作原理等因素，致使目前基于AlGaN的紫外-红外双波段探测器响应度低，暗电流大。本项目提出一种新型的基于AlGaN/BP/MoS2范德华异质结的紫外-红外双波段探测器，即利用范德华异质结无需晶格匹配这一特点，将二维BP/MoS2 pn结和三维AlGaN PN结通过堆叠方式形成npPN型背靠背光电二极管，以此实现红外和紫外光的高效同时探测。本项目将研究高质量高Al组分AlGaN材料的外延生长和缺陷控制规律，研究AlGaN掺杂、二维BP和MoS2层厚以及界面缺陷对器件探测性能的影响规律。通过能带工程、界面缺陷控制并完善材料外延生长、二维材料定点转移和器件制备工艺，最终研制出高性能、快速响应的单片集成紫外-红外双波段探测器原型器件，为发展高性能的双波段探测器件提供新思路和新方法。

紫外-红外双波段探测器在军事领域和国民经济中均有着广泛的应用前景。然而，由于材料晶体质量、器件结构及工作原理等因素，致使目前基于AlGaN的紫外-红外双波段探测器响应度低，暗电流大。本项目提出并研究了一种新型的基于AlGaN/BP/MoS2范德华异质结的紫外-红外双波段探测器，将二维BP/MoS2 pn结和三维AlGaN PN结通过范德华堆叠方式形成npPN型背靠背光电二极管。本项目主要研究了高质量高Al组分AlGaN材料的外延生长和缺陷控制规律，获得了位错密度1.8×109 cm-2、Al组分52%的高质量AlGaN薄膜。制备了AlGaN基日盲紫外探测器，器件的响应中心波长为269 nm，截止波长为280 nm，最高响应度可达2 A/W。制备了GaN基HEMT结构紫外探测器，器件的波长响应范围为225-400 nm，响应中心波长在300 nm左右，最高响应度达2000 A/W，具有极高的内部增益。研究了二维BP和MoS2层厚依赖的光电性质层，发现MoS2的导电类型会随着层厚的增大逐渐从n型变成双极性，最后变成p型。制备了MoS2/BP异质结器件，器件在近红外到短波红外均显示较好的光电响应。